The popular claim that 'logical' people are left-brain-dominant and 'creative' people are right-brain-dominant is not supported by neuroscience. A widely-cited 2013 study out of the University of Utah, analyzing resting-state brain scans from over 1,000 people, specifically looked for evidence of individuals with a globally dominant hemisphere and found no such pattern — both hemispheres are active and interconnected during virtually all cognitive tasks, including ones popularly assigned to 'one side,' like language (which does have some regions more concentrated in one hemisphere, but nowhere near a clean creative/logical split) or spatial reasoning.
The kernel of truth buried in the myth is real: there is hemispheric lateralization for some specific, narrow functions — language production is more concentrated in the left hemisphere for most right-handed people, for instance. But that narrow, specific lateralization is a completely different claim from 'creative people use their right brain more,' which the popular version stretched far beyond what the actual research supports.
Nielsen's team set out to directly test the popular personality claim, not just the narrower question of regional specialization that neuroscience already accepted. They analyzed resting-state connectivity scans from 1,011 people, specifically looking for evidence that some individuals show a globally more-connected left hemisphere and others a globally more-connected right hemisphere — the pattern the popular "left-brained/right-brained" personality claim would require. They found no such pattern at all: connectivity within specific functional networks varied between people, but there was no evidence of individuals having an overall dominant hemisphere linked to personality traits like creativity or logic.